1. Field of the Invention
This invention relates to an extraction cleaning machine and, more particularly, to an upright extraction cleaning machine.
2. Description of Related Art
Upright extraction cleaning machines have. been used for removing dirt from surfaces such as carpeting, upholstery, drapes and the like. The known extraction cleaning machines can be in the form of a canister-type unit as disclosed in U.S. Pat. No. 5,237,720 to Blase et al. or an upright unit as disclosed in U.S. Pat. No. 5,500,977 to McAllise et al. and U.S. Pat. No. 4,559,665 to Fitzwater.
Current upright extraction cleaning machines can be made easier to use by limiting the weight and number of components, such as fluid storage tanks, on the pivoting handle of the upright cleaning machine. Reducing the weight that a user must support as the handle is tilted rearwardly can also lower the center of gravity for the machine, which results in a better feel to the user.
Furthermore, the current extraction cleaning machines can be made easier to use and better adapted for a variety of cleaning conditions. For example, none of the current extraction cleaning machines includes an elevator responsive-to-handle position for restraining a floating roller-type agitation brush, which is automatically height adjustable in response to changes on the surface being cleaned. Another problem inherent with the known extraction cleaning machines is the difficulty of filling and emptying the fluid supply chamber and fluid recovery chamber, particularly with bladder-within-a-tank type assemblies. Further, none of the current upright extraction cleaning machines are simply convertible to a pre-spray applicator for directing cleaning solution to and agitating the surface to be cleaned without applying suction. Finally, current extraction cleaning machines do not use a the same motor to drive an agitation brush as well as an impeller. Is some cases a separate motor is used. In other cases, a turbine is used to drive the agitation brush or brushes which diminishes the suction power available to extract the dirty solution from the floor surface.
A more recent development in the extraction cleaning industry is the use of steam or hot water as a cleaning agent. The cleaning machine incorporates a boiler or other means for generating steam or hot water, which is pumped to an applicator where it is brought into contact with the surface being cleaned. Because the steam is airborne, it may be unsafe to include detergents and the like in the cleaning solution. Further, while the steam systems have the advantage of creating a temperature that effectively kills a wider range of microbes, bacteria, microorganisms, and mites, the steam systems generally suffer from poor cleaning performance. Additionally, the high power requirement for generating steam may not be sufficient with ordinary 120 V power supplies for running a vacuum motor as well as the steam generator, so cleaning performance is further hindered. Also, by adding a heater to a fluid supply chamber, the user may be inconvenienced by the amount of time required to heat the contents of the supply chamber to the desired temperature. Conversely, conventional detergent cleaning systems are somewhat effective at cleaning surfaces, but could be made more effective by raising the temperature of the cleaning solution to some temperature below the boiling point. There is an optimal temperature at which cleaning performance is maximized without causing damage to carpets or setting stains. This temperature is around 150xc2x0 Fahrenheit.
According to the invention, a portable surface cleaning apparatus comprises a base housing adapted for movement along a surface to be cleaned, an upright handle pivotally mounted to the base housing, a liquid dispensing system and a liquid recovery system. The liquid dispensing system includes a liquid dispenser associated with the base module for applying liquid to a surface to be cleaned, a liquid supply tank for holding a supply cleaning liquid and a liquid supply conduit fluidly connected to the liquid supply tank and to the dispenser for supplying liquid to the dispenser. The liquid recovery system comprises a recovery tank removable mounted on the base housing and having a liquid recovery chamber for holding recovery liquid, a suction nozzle associated with the base housing adapted to draw dirty liquid from the surface to be cleaned and a working air conduit extending between the recovery chamber and the suction nozzle and further includes a vacuum source in fluid communication with the recovery chamber for generating a flow of working air from the nozzle through the working air conduit and through the recovery chamber to thereby draw dirty liquid from the surface to be cleaned through the nozzle and working air conduit and into the recovery chamber to thereby recover dirty liquid from the surface to be cleaned.
In accordance with one embodiment of the invention, the base housing includes a socket for selectively receiving the recovery tank at an enclosed chamber formed longitudinally of the socket with the vacuum source mounted in the enclosed chamber. The enclosed chamber is preferably positioned forwardly of the socket.
In one embodiment, a brush roll is mounted on the housing and the vacuum source includes a motor that is drivingly connected to the brush roll to drive the brush roll.
Further, the base of the housing includes lower section and a motor cover which are connected together to define the chamber therebetween. The vacuum source includes a suction fan driven by the motor and the chamber has a suction fan-holding cavity and further comprises an air inlet conduit connected to the suction fan-holding cavity.
In another embodiment, the liquid supply tank and the recovery tank are both removably mounted to the base housing. Preferably, the liquid supply tank is in the form of a flexible bladder that is mounted within the recovery tank.
In a preferred embodiment of the invention, a detergent supply tank for holding a supply of concentrated cleaning solution is operably fluidly connected to the liquid supply conduit for supplying a mixture of concentrated cleaning solution and water to the dispenser. The detergent supply tank is also mounted on the base housing.
In yet another embodiment of the invention, the liquid supply tank is in the form of a flexible bladder that is mounted within the recovery tank.
Still further according to the invention, a multi chamber tank is removably mounted to the base housing and includes at least one of the recovery tanks and the liquid supply tank, preferably both of the recovery tank and the liquid supply. Preferably, the multi chamber tank is mounted within the socket base housing.